There are many methods currently in use to measure surface reflectance and surface roughness. Some methods were described in the background paragraph of my prior U.S. Pat. No. 4,770,536. Other methods are based upon triangulation and interferometric principles. While the Reflective Photometry Instrument described in U.S. Pat. No. 4,770,536 does measure reflectance, its performance is further enhanced by introduction of additional features to be described below. One major objective of of the present invention is to provide a controllable distance, e.g. a constant distance, and if desired, a constant angle between the instrument and the surface under examination at which surface reflectance or emission can be measured.